Holder or quill for holding the rotating tools of engraving-machines.



No. 818,993. PATENTED APR. 24, 1906. M. BARR.

HOLDER OR QUILL FOR HOLDING THE ROTATING TOOLS OF ENGRAVING MACHINES.

APPLICATION FILED AUG29,1904.

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MARK BARR, OF COWLEY, NEAR UXBRIDGE, ENGLAND, ASSIGNOR TO THE LINOTYPE COMPANY LIMITED, OF LONDON, ENGLAND.

HOLDER OR OUlLL FOR HOLDING THE ROTATING TOOLS OF ENGRAVlNG-MACHTNES.

Specification of Letters Patent.

Patented April 24, 1906.

Original application filed May 31, 1901, Serial No. 62,61 L. Now Patent No. 774,027, November 1, 1904. Divided and this application filed August 29, 1904. Serial No. 222,590.

To all //-/1 out it may concern.-

Be it known that I, MARK BARR, residing at The Cedars, Cowley, near Uxbridge, in the county of Middlesex, England, have invented certain new and useful Improvements in IIolders or Quills for Holding the Rotating Tools of Engraving-Machines; and I do here by declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to improvements in holders or quills for holding the rotating tools of engraving-machines, the par ticular class of holder or quill to which it appertains being that in which the said devices at their gripping ends are split to render them flexible and externally coned to admit of the flexible jaws between the splits being forced inward onto the tool by an internal cone moved onto or having moved into it the said externally-coned part. Hitherto the construction of these devices has been such that the necessarily absolute concentricity of the tool has been exceedingly difficult or almost impossible of attainment, and in consequence thereof great loss has been incurred by the frequent breakage of the engraving-tools, these tools from the nature of the work they are required to execute being exceedingly minute and delicate. From investigations made by me I am convinced that much of this absence of concentricity is due to the fact that as the outer ends of the abovenamed jaws are disunited from each other they are capable of unsymmetrical displace ment or compression when they are tightened upon the tool and that such unsymmetricalness readily occurs if a particle of grit is present between the juxtaposed conical surfaces of the jaws and internal cone. Moreover, the above-named disunited arrangement of the jaws renders them too flexible and liable to lateral deflection when the tool is exposed to much lateral pressure.

The object of the present invention is to overcome all of the aforesaid difficulties, and this result is attained by the means hereinafter fully described and more particularly pointed out in the claims.

In the accompanying drawings, which are to be taken as part of this specification and read therewith, Figure 1 is a view showing in elevation the improved tool-holder or quill and in vertical section the surrounding portions of the engraving-machine in which the said tool-holder is mounted, these portions being fully described in the specification of Letters Patent No. 774,027, dated November 1, 1904, from which the present application is a divisional one. Fig. 2 is a plan of the tool-holder drawn to a scale larger than that to which Fig. 1 is drawn.

1 is the quill, whose upper end is provided with four slots 2, between which are left the intervening jaws 3. The slots 2 as distinguished from the slots of existing quills of the same class do not extend to the extremity of the gripping end of the quill, but terminate at a position adapted to leave an unbroken annulus or ring 4 between such extremity and the roximate ends of the slots.

5 is t e external cone formed upon the quill 1 and adapted to fit into a corresponding internal cone formed in a bush 6, adapted to rotate in a conical bearing-block 7, rigidly but removably secured in a socket 8.

The quill 1 is prevented from rotatin independently of the bush 6 by a pin 9 (winch is fast in the said bush) engaging with a groove or keyway 10, (represented in dotted lines in Fig. 1,) formed in the quill. At its lower end the quill 1 terminates in a screw 11, with which engages the upper end of a long nut 12, which abuts against an annular shoulder 13, formed within the bush 6. The lower end of the long nut terminates in a square portion 14, by which the said nut may be turned for securing or releasim the tool 15.

The outside of the aws 3 besides being externally coned at 5, as previously described, is also coned in the reverse direction from the larger part of the said cone down to and including the ring 1, and on this coned part is fitted in driving contact therewith a correspondingly internally coned collar 16, having a flange 17. Over this collar 16 fits an oil-stop 18, whose downwardly-depending edge or rim is sprung into an annular groove 19, formed in the upper part of the socket S. The oil-stop 18 has a central opening 20 sufficiently large to allow the collar 16 to rotate within it without contacting with the said stop, and the flange 17 just below the said opening serves to project any lubricant which may reach it outward toward the rim of the stop 18. At its upper end the collar 16 is externally screw-threaded to receive a circular shield 21, having a downwardlysloping top and depending rim 22, which latter is adapted to rotate just outside and clear of the oil-stop 18, the said shield serving to prevent fragments of material detached by the tool 15 from entering the oil-cavities.

It will be observed that by the jaws 3 being integrally united to ether at their extreme ends, as previously described, the said jaws are provided with sufficient support to secure them a ainst the before-mentioned unsymmetrica displacement or distortion.

The details represented in the accompanying drawings which are not herein described are fully described in the before-mentioned specification and form no part of the present invention.

I claim 1. In a rotating tool-holder having an axial hole extending completely through it and adapted to receive the tool, the combination of jaws integral with the holder and flexible in a direction radial to the axial hole; intermediate slots radiating from the axial hole and alternating with the jaws, and extending in one direction toward, but not reachin one end of the said holder; and a ring rigid y secured to the jaws and serving to both unite the jaws and close the ends of the slots at the 2. In a tool-holder having an external cone and an axial hole the latter extending completely throu h the holder, the combination of said cone; exible jaws intermediate slots alternating with the jaws and extending in one directlon toward, but not reaching, one end of. the said holder; a ring rigidly secured to the aws and serving to both unite the jaws and close the ends of the slots at the opposite end of the holder, and adapted to maintain the proximate ends of the jaws concentric with the remaining portions of the holder; and a cone adapted to cooperate with the first-named cone so as to symmetrically compress the jaws onto the tool.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

MARK BARR.

Witnesses:

HENRY HART, T. J. OSMAN. 

